Setting Up and Using Magneto "Blip" Switches in OFF

[RAF_Louvert 101]

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As some of you will remember in a post a while back it was discovered that, contrary to popular belief, our WWI RL conterparts did quite a bit of switching on and off of their engines during flight and combat maneuvers. Immediately following that realization I set up a pair of buttons on the top of my Logitech to act as magneto blip switches. I mapped "Shift+M" to one and "Ctrl+M" to the other and began flying the various OFF planes to see what affect using this feature has. I am here to report that it has quite a noticeable affect, particularly with the rotary-powered kites. Nearly every maneuver that requires a rapid change in direction will benefit from momentarily killing power to the magnetos, thus reducing the effects of forward motion, and more importantly gyroscopic precession as that spinning mass slows down. And this all happens much faster when you cut the mags rather than reducing throttle. I have discovered after my last couple of weeks of flying "with the mags" that it is another edge you have at your disposal to combat the AI. You can go about 3 seconds with the mags off and still have the engine fire back up. Longer than that and you will likely kill the engine completely and will then have to go into a dive in order to get enough speed to windmill the prop and restart in flight, (which they also did in RL back in the Great War). I had to map two separate switches, an "ON' and an "OFF", because some of the planes are modeled with one mag while others are modeled with two. With this set-up I simply hit the "OFF" switch twice in quick succession which shuts down each and every plane we have PDQ. Conversely, hitting the "ON" switch quickly twice brings them back up to full power just as fast. Give it go, and see what you think. For me, it has now become part of my regular flying practice.

 

Cheers!

 

Lou

 

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[Bandy 3]

Sounds like an interesting mod. Rotary pilots blipping was constant to maintain formation, etc. Should be included in an official patch IMHO, or at least an option to activate the blip,

i.e. Blip Switch active/inactive, though only rotaries had blip switches.

 

You could also map the Blip switch to a joystick button, and I know with my Logitec at least I can program repeats, so one hit of the js button means two.

 

The 3 second blipped engine leading to engine-kill is a limitation though, and this time should be increased to maybe 10 secs for it to be realistic, but I'm sure somebody has more accurate knowledge here. Blipping the engine AFAIK didn't kill it, at least not within 3 secs.

Edited February 7, 2010 by Bandy

[RAF_Louvert 101]

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I agree Bandy, this would be a good addition to the OFF settings. Also, as far as killing the engine due to mags being shut off, while it would not cause it to kill for that reason, it could cause the engine to flood out as raw fuel and oil loaded up the cylinders. This happened far too often in RL to pilots who neglected to lean out the fuel mixture when running with the mags off for too long a time, at which point all they could do was shut off fuel, go into a long glide to get the prop windmilling well, then fire up the mags to clear out the cylinders...and hope it restarted afterwards.

 

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[RAF_Louvert 101]

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BTW, here is the quote from Flt. Commander W.G. McMinnies 1918 book, "Practical Flying: Complete Course of Flying Instructions", which I posted in the thread I mentioned earlier concerning the practice of cutting the engine. This is a short excerpt from the Commander's recap at the end of the book that illustrates the point, (and the practice is mentioned repeatedly throughout the 200+ pages of this text):

 

 

Stage 9 Advanced Flying

 

1.—Every time you go up solo try and do something you have never done before, i.e., go up higher, or for a longer flight, or in worse weather, or practise aerobatics.

 

2.—First perfect yourself in landing on a mark with engine cut off.

 

3.—For this, "S" turns, spirals and vertical banks with and without engine must be practised.

 

4.—Practise climbing turns and stalling turns. The latter are performed by pulling the machine up on its nose and then banking and ruddering in the desired direction. The engine can be cut off during the manoeuvre. Modifications of this manoeuvre with the engine on result in cartwheels and Immelman turns in which the machine does an about turn.

 

5.—In all aerobatics avoid too sudden changes of direction of the machine, i.e., pull the machine out of a dive gently and gradually.

 

6.—To zoom, fly level at full speed, and then pull the stick back. At the top of the zoom ease the stick forward.

 

7.—A hoiked turn is a curving zoom, but you should know your machine, and practise this at 1000 ft.

 

8.—To loop, put the nose down to 85 m.p.h., and pull the stick straight back into your chest. When over, cut out the engine, and pull the machine out of the dive gently. The latter part of the pull back is quicker than the first in starting the loop.

 

9.—To spin, cut out the engine, and stall the machine level with the nose on the horizon. Kick on rudder, and pull the stick right back into the chest. To come out, centre the rudder gently, and ease the stick forward.

 

10.—To roll, get up speed either with or without engine, kick on rudder, and pull the stick right back.

 

11.—To turn very quickly, switch off momentarily, kick on rudder without any bank, which will pull the machine up and twist its nose round in the desired direction. She will get into a spin if not righted immediately. Then switch on.

 

12.—To sideslip or partially glide sideways, switch off, put on bank in one direction and rudder in the other. The machine will glide sideways in the direction in which the stick is held.

 

13.—The falling leaf descent is done with the engine off, and the stick held back in the pilot's chest. After she stalls, she can be allowed to gain speed, and then stalled again. If the engine stops, dive to restart it.

 

14.—Diving is best done with the engine off. Put the stick forward, and hold it there while the speed increases. Pull out of a vertical dive very gradually.

 

15.—Try all advanced flying at a height of 2000 ft. or 3000 ft.

 

16.—Practise sham flights and aerobatics with other pupils if your instructor thinks you are good enough. Practise approaching machines unseen, and always take note of the machines in the air about you.

 

Cheers!

 

Lou

 

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[Bandy 3]

That's a really good introductory list to CAM. And more interesting because while the basics are the basics, so much must have changed from airplane to airplane as technology got better (engines and aeronautics).

 

10.—To roll, get up speed either with or without engine, kick on rudder, and pull the stick right back.

 

That's a flick roll, there was a big thread on this a few months back. Sorry, off topic...

Edited February 7, 2010 by Bandy

[Fortiesboy 3]

I've been flying all the rotary planes in a similar way to this for some long while now.

It's been a small cheat though, cos all I did was use two buttons on my cougar hotas.

 

Press first time and i have full throttle; press again and i have one third throttle .

Press a second button and i have tickover.

 

Using only those three buttons ( and not moving the throttle stick ) makes dogfighting in a camel or Dr1 very interesting.

[RAF_Louvert 101]

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Fortiesboy, I've been flying OFF with a throttle blip switch as you describe ever since I loaded the sim. But the mag blip is a bit different in that it gives you a far quicker response than throttle. That was one of the points I was making in my first post, that it is this quicker response which makes the difference is some of the maneuvers. You should give it a try, because if you like the throttle blip you are really going to like the mag blip.

 

Cheers!

 

Lou!

 

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[Bletchley 8]

Thanks for the interesting post, Louvert :)

 

But we have to be a bit careful with the terminology. Phrases such as "with engine cut off", "without engine", "engine can be cut off" and "cut out the engine" do not always mean that the blip switch was used. It was normal practice with the rotary engines to cut off the fuel supply to the engine by pulling back on the 'fine adjustment' (a lean cut) or by using the on/off fuel cock, and this was certainly used for any prolonged period (such as, in a dive or in 'falling leaf' descent). The blip switch was supposed to be limited to those times when the engine had been throttled back, either when taxiing on the ground or when throttled back for landing - using the blip switch from full power could damage the engine by the stresses imposed, and lead to fire under the cowling as the excess fuel was ejected from the exhaust valves when the blip was released. These instructions were given to Naval 8 pilots by their CO, Christopher Draper:

 

"DON'T 'blip' except when throttled right down. It is extremely bad flying and puts unnecessary strain on the whole machine."

 

"DON'T switch off at any time in the air, or the plugs will oil up."

 

McMinnies use of the phrases "switch off" and "switch on" in no.11 does, however, sound very like a recommendation to use the blip switch, and the use of blip switch combined with a slide-slip to control the rate of descent was common practice for landing after throttling back (no.12). So, I guess use of the blip switch could vary in practice and from one squadron or pilot to another - but it was not encouraged officially as standard practice from full power. The blip switch was necessary because of the higher idle speed (around 800 rpm in the air) of rotary engines, as compared to stationary engines (which had magnetos, but no blip switch).

 

Bletchley

[RAF_Louvert 101]

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Thanks for the reply and info Bletchley. It certainly is an interesting, confusing, and contested subject. I know many years ago I watched a restored/replica Sopwith Camel with the Clerget flying and it was quite evident from the sound that the pilot was blipping at least one of the ignition switches on and off to control speed. As I recall you could cut out about half the cylinders by blipping one switch, and all the cylinders by blipping both. But I may be in error about that. I assume he was also fiddling with fuel mixture at the same time so as not to load up the engine with raw petrol.

 

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[Bletchley 8]

It might have been the Sopwith Camel with the 150/160 hp Gnome Monosoupape (there is another flyable Camel, with a 110 hp Le Rhone in the USA, but I am not aware of there being one with a Clerget). The Gnome Monosoupape has no throttle, but the 160 hp version has two magneto switches - one standard on/off switch, and a second one that could be used to change the firing sequence of the cyclinders to cut out a number of selected cylinders in each cycle, and reduce the power by 1/8, 1/4 or 1/2. It also had a fine adjustment and a blip switch, I think, as standard. I don't think this Monosoupape version of the Camel was used much, if at all, in a combat role.

 

The Le Rhone had only one magneto switch, and a blip switch (the two are not the same - the blip switch was a button on the spade grip).

 

The Clerget did have two magneto switches (so if one failed, the other one would at least keep the engine running), and a blip switch.

 

The Oberursel used on the Fokker E.III also had a blip switch, both a throttle & a fine adjustment, and a 'selector' switch that could be used to select and isolate a single cylinder - this was not intended as a form of power management, however, as the intended use was to isolate and cut-out a cylinder that was mis-firing.

 

Bletchley :)

[RAF_Louvert 101]

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Outstanding info Bletchley and many thanks for it! I am adding it to my resource library. As to the Camel I saw fly, you are very likely correct about the engine Sir. It was many years ago and my memory is not what it use to be...or maybe it is, I don't really remember.

 

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